diff options
| author | Pablo Neira Ayuso <pablo@netfilter.org> | 2012-06-07 13:31:25 +0200 |
|---|---|---|
| committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2012-06-16 15:09:08 +0200 |
| commit | 8c88f87cb27ad09086940bdd3e6955e5325ec89a (patch) | |
| tree | 1acfa54ba78602eb4eb053110ffc0a54025318c7 /net/netfilter/nf_conntrack_netlink.c | |
| parent | 9cb0176654a7dc33a32af8a0bc9e0b2f9f9ebb0f (diff) | |
netfilter: nfnetlink_queue: add NAT TCP sequence adjustment if packet mangled
User-space programs that receive traffic via NFQUEUE may mangle packets.
If NAT is enabled, this usually puzzles sequence tracking, leading to
traffic disruptions.
With this patch, nfnl_queue will make the corresponding NAT TCP sequence
adjustment if:
1) The packet has been mangled,
2) the NFQA_CFG_F_CONNTRACK flag has been set, and
3) NAT is detected.
There are some records on the Internet complaning about this issue:
http://stackoverflow.com/questions/260757/packet-mangling-utilities-besides-iptables
By now, we only support TCP since we have no helpers for DCCP or SCTP.
Better to add this if we ever have some helper over those layer 4 protocols.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'net/netfilter/nf_conntrack_netlink.c')
| -rw-r--r-- | net/netfilter/nf_conntrack_netlink.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c index d304d591795..8be0ab9b475 100644 --- a/net/netfilter/nf_conntrack_netlink.c +++ b/net/netfilter/nf_conntrack_netlink.c @@ -46,6 +46,7 @@ #ifdef CONFIG_NF_NAT_NEEDED #include <net/netfilter/nf_nat_core.h> #include <net/netfilter/nf_nat_protocol.h> +#include <net/netfilter/nf_nat_helper.h> #endif #include <linux/netfilter/nfnetlink.h> @@ -1751,6 +1752,9 @@ static struct nfq_ct_hook ctnetlink_nfqueue_hook = { .build_size = ctnetlink_nfqueue_build_size, .build = ctnetlink_nfqueue_build, .parse = ctnetlink_nfqueue_parse, +#ifdef CONFIG_NF_NAT_NEEDED + .seq_adjust = nf_nat_tcp_seq_adjust, +#endif }; #endif /* CONFIG_NETFILTER_NETLINK_QUEUE */ |